linux宿主机：F9
arm：mini2440
按键中断驱动：用的是GPIO中的GPF6（EINT6）
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/irq.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/platform_device.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>
#define DEVICE_NAME "keys"
#define KEY_DOWN 0
#define KEY_UP 1
static volatile int ev_press = 0;
static volatile int key7_status;
static DECLARE_WAIT_QUEUE_HEAD(key_waitq);
struct key_irq_desc {
int irq;
int pin;
int pin_setting;
int number;
char *name;
};
static struct key_irq_desc key_irqs = {
IRQ_EINT6, S3C2410_GPF6, S3C2410_GPF6_EINT6, 6, "KEY7"
};
static irqreturn_t key_interrupt(int irq, void *dev_id)
{
if(!s3c2410_gpio_getpin(key_irqs.pin))//按下，低电平则为真
{
if(key7_status == KEY_UP)
{
key7_status = KEY_DOWN;
ev_press = 1;
printk(DEVICE_NAME "enter in irq!\n");
wake_up_interruptible(&key_waitq);
}
}
return IRQ_RETVAL(IRQ_HANDLED);
}
static int keys_open(struct inode *inode, struct file *file)
{
int ret;
ret = request_irq(key_irqs.irq, key_interrupt, IRQF_TRIGGER_FALLING, key_irqs.name, NULL);
if(ret)
{
disable_irq(key_irqs.irq);
free_irq(key_irqs.irq, NULL);
return -EBUSY;
}
key7_status = KEY_UP;
printk(DEVICE_NAME "enter in open!\n");
return 0;
}
static int keys_close(struct inode *inode, struct file *file)
{
disable_irq(key_irqs.irq);
free_irq(key_irqs.irq, NULL);
return 0;
}
static int keys_read(struct file *file, char __user *buf, size_t count, loff_t *offp)
{
unsigned long ret;
if(!ev_press)
{
if(file->f_flags & O_NONBLOCK)
return -EAGAIN;
else
wait_event_interruptible(key_waitq,ev_press);
}
ev_press = 0;
ret = copy_to_user(buf, (void *)key7_status, min(sizeof(key7_status), count));
memset((void *)key7_status, KEY_UP, sizeof(key7_status));
printk(DEVICE_NAME "enter in read!n");
return ret? -EFAULT : min(sizeof(key7_status), count);
}
static int keys_poll(struct file *file, struct poll_table_struct *wait)
{
unsigned int mask = 0;
poll_wait(file, &key_waitq, wait);
if(ev_press)
{
mask |= POLLIN | POLLRDNORM;
}
return mask;
}
static struct file_operations keys_fops = {
.owner = THIS_MODULE,
.open = keys_open,
.release = keys_close,
.read = keys_read,
.poll = keys_poll,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &keys_fops,
};
static int __init keys_init(void)
{
int ret;
ret = misc_register(&misc);
printk(DEVICE_NAME "\tinitialized!\n");
return ret;
}
static void __exit keys_exit(void)
{
misc_deregister(&misc);
}
module_init(keys_init);
module_exit(keys_exit);
MODULE_LICENSE("GPL");
测试程序为：
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
int main(int argc, char **argv)
{
int fd;
int key_status;
fd = open("/dev/keys", 0);
if(fd < 0)
{
printf("Open Keys Device Faild!\n");
exit(1);
}
while(1)
{
int i;
int ret;
fd_set rds;
ret = select(fd + 1, &rds, NULL, NULL, NULL);
if(ret < 0)
{
printf("Read Keys Device Failed!\n");
exit(1);
}
if(ret == 0)
{
printf("Read Keys Device Timeout!\n");
}
else if(FD_ISSET(fd, &rds))
{
ret = read(fd, key_status, sizeof(key_status));
if(ret != sizeof(key_status))
{
if(errno != EAGAIN)
{
printf("Read Key Device Failed!\n");
}
continue;
}
else
{
printf("Key%d is DOWN\n", key_status+1);
}
}
}
close(fd);
return 0;
}
驱动能够insmod成功，当运行测试程序后，超级终端会显示报错信息：
[root@FriendlyARM plg]# ./key7_2_test
keysenter in open!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
keysenter in irq!
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c3028000
[00000000] *pgd=339c6031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#5]
Modules linked in: key7
CPU: 0 Tainted: G D (2.6.29.4-FriendlyARM #6)
PC is at __copy_to_user+0x84/0x314
LR is at keys_read+0x134/0x14c [key7]
pc : [<c0129424>] lr : [<bf00028c>] psr: 00000013
sp : c306bef4 ip : 0000001c fp : c306bf54
r10: 00000000 r9 : c306a000 r8 : 00000000
r7 : 00000004 r6 : c306bf78 r5 : bf000aac r4 : 00000004
r3 : 00000000 r2 : ffffffe4 r1 : 00000000 r0 : 00000000
Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: c000717f Table: 33028000 DAC: 00000015
Process key7_2_test (pid: 579, stack limit = 0xc306a268)
Stack: (0xc306bef4 to 0xc306c000)
bee0: bf000aac c306bf78 00000004
bf00: 00000000 00000000 00000004 00000000 00000004 bf00028c c3b8f378 bef63ca0
bf20: 00000000 00000000 00000000 00000000 c306a000 c3055600 00000000 c306bf78
bf40: 00000003 c0028008 c306bf74 c306bf58 c0088468 bf000168 00000000 00000000
bf60: c3055600 00000003 c306bfa4 c306bf78 c0088580 c00883c4 00000000 00000000
bf80: 00000000 00000000 0000008e 00008600 00000000 000083f4 00000000 c306bfa8
bfa0: c0027e60 c0088544 00008600 00000000 00000003 00000000 00000004 00000001
bfc0: 00008600 00000000 000083f4 00000003 00000000 00000000 40025000 bef63d34
bfe0: 00000000 bef63c90 00008598 400dda3c 60000010 00000003 00000000 00000000
Backtrace:
[<bf000158>] (keys_read+0x0/0x14c [key7]) from [<c0088468>] (vfs_read+0xb4/0xe8)
r8:c0028008 r7:00000003 r6:c306bf78 r5:00000000 r4:c3055600
[<c00883b4>] (vfs_read+0x0/0xe8) from [<c0088580>] (sys_read+0x4c/0x84)
r7:00000003 r6:c3055600 r5:00000000 r4:00000000
[<c0088534>] (sys_read+0x0/0x84) from [<c0027e60>] (ret_fast_syscall+0x0/0x2c)
r6:000083f4 r5:00000000 r4:00008600
Code: e4915004 e4916004 e4917004 e4918004 (e491e004)
keysenter in irq!
---[ end trace 1d63f8cfc03fdeb0 ]---
Segmentation fault
[root@FriendlyARM plg]#
我想请问大侠们出了什么问题，还有请问大家有没有比较好的办法进行内核调试，或者驱动调试，因为我不知道该怎么改，谢谢！
